hookooekoo
Senior Retro Guru
Airspace restrictions are designated in feet.
Advice please on chainset ratios
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Well that was a bit of a rabbit hole which I’ve finally dug myself out of.
I did back to back tests of my original 44/18 & then 44/16 on my local 10mile exercise loop it’s a neat in and out of our little Wolds valley with a good mix of climbs.
Although the 16 did get me up to a higher speed on the flat & downhill, it broke me on the 9 & 10 percent climbs, (I had to get off or fall off!)
So it’s back to 44/18, at least till I get fitter.
Here’s a snip from Strava of one of the hills showing the data from the 44/18 & my PB with fully 2x10 geared more modern road bike, maybe I should have left well alone.
Cheers @hookooekoo
I did back to back tests of my original 44/18 & then 44/16 on my local 10mile exercise loop it’s a neat in and out of our little Wolds valley with a good mix of climbs.
Although the 16 did get me up to a higher speed on the flat & downhill, it broke me on the 9 & 10 percent climbs, (I had to get off or fall off!)
So it’s back to 44/18, at least till I get fitter.
Here’s a snip from Strava of one of the hills showing the data from the 44/18 & my PB with fully 2x10 geared more modern road bike, maybe I should have left well alone.
Cheers @hookooekoo
hookooekoo
Senior Retro Guru
It was always going to be a challenge and a compromise when compared to more modern setups (double for road or triple for MTB). But in my opinion that's part of the appeal of riding a bike that has fewer gears. I'm on 44 x 17 fixed at the moment, and I find that's OK for hills that are marked as single chevron (1/7 to 1/5), as long as the steep bits are fairly short. However, my thighs will be burning a bit by the time I get home. Embrace the challenge, and plan your routes and gearing so that you can ride most of the circuit. After a few weeks of regular rides you should find your fitness improves. My own example is that a month or so back I did a ride that took my legs a week or more to recover from, but I can now do the same ride and be recovered after half a week. And when you don't have huge numbers of gears to select from, the changes in fitness are more obvious, because you can more easily remember what you achieved last time. And we should all be looking to be at peak fitness, because winter is coming, and covid is still around.
One thing you might not have considered is that third gear on your hub is direct drive. So if you set up the gearing so that you're comfortable cruising in third gear, then you can spend most of the time in the most efficient gear.
One thing you might not have considered is that third gear on your hub is direct drive. So if you set up the gearing so that you're comfortable cruising in third gear, then you can spend most of the time in the most efficient gear.
hookooekoo
Senior Retro Guru
Sheldon Brown says third gear is 100% for all of the four speed Sturmey Archer hubs. I think 100% usually means it's direct drive in that gear (internal gears are locked out and unused). So it should be the same efficiency as single speed or fixed. You can't get any higher efficiency than that.
I suppose you could ask the guy who serviced your hub. He would know for sure if it's direct drive.
I suppose you could ask the guy who serviced your hub. He would know for sure if it's direct drive.
hookooekoo
Senior Retro Guru
Sturmey Archer four speed wide ratio. Only three ratios are listed, so the fourth (unlisted) is probably direct drive.
Exploded diagram
Exploded diagram
The prime (or at least odd) number idea is that you never get a repeating pattern of chain/sprocket/chainring engagement. Tihs repeating patter can cause excessive wear at certain points. A 37-17 setup sees things constantly rolling with no rapid repeat of the pattern. A 40-20 setup would repeat every rotation. That would mean the same sprocket tooth taking the load each time at the back. It most obvious on a singlespeed. I always run something like 2:1 front to rear, but add an extra tooth (e.g. 32/16, 36/19) to avoid the repeat every crank rotation.
